I've noticed

I've noticed that the discussions on the elantra link are much different than the discussions o nthe tiburon link. The elantra link is more troubleshooting, and how to fix things, while the tiburon link is more performance, upgrade discussions. Anyways, I'm writing this because I am wondering if any of you can tell me any performance websites for the elantra.(Just bought an '04 elantra gt)

i believe you have the same engine as a i4 tib there may me some universal mods but you are going to have to look into it.

try hyundaiperformance.com
And yeah, the I4 Tib is almost the same powertrain-wise, so look for threads for that.

Try Drivers & Believers (http://egt.gwebworks.com/index.shtml), a site dedicated to Elantra GTs. There is no forum, but somewhere around on the site you can sign up for a mail list which is almost as good (and you can browse the archive). They also have a Garage section that has little customizations and stuff, and a links page with links to tuner parts sites and stuff. I think I read the guy who started this site totaled his Elantra and bought a Tibby, so it may not be as active as it could be, but there's still a lot of interesting stuff there.